This rotary encoder has a 1024 pulse per rotation rotary encoder outputs gray code which you can interpret using a microcontroller and find out which direction the shaft is turning and by how much. This allows you to add feedback to motor control systems.
This is a 1 foot communication cable extension that mates with the EM406 and EM401.
This is a basic breakout board for the FTDI FT232RL USB to serial to work with official Arduino and cloned 5V Arduino boards.